Mixer



J. JOHNSON.

MIXER.

APPLICATION FILED FEB. 21, 1919.,

1,353,165, PatentedSept. 21, 1920.

UNITED STATES PATENT i orrice.

JOHN .ronnson; or 300mm, NEW YORK mrxm Continuation of applicationSerial No. 102,110, fl1ed June 7, 1916. Renewed Februaryzl, 1919, serialNo. 278,509. -This applicationfiled February 21, 1919. Serial No.278,467.

To all whom z't may concern.

Be it known that I, JOHN JOHNSON, -a

citizen of 'the'United States, residing at Brooklyn, New York, haveinvented cer tain new and useful Improvements in Mixers, of which thefollowing is a clear, full and exact description.

My'invention relates to mixers and particularly to rotary mixers for usein mixing solids, liquids or gases, with liquids, and is a continuationof m application Serial No. 102,110, filed June th, 1916, renewed Feb.21, 1919, Serial No.v278,509, as to common subject-matter. V

Rotary mixers as hitherto constructed have usually tended in operationto impart to the contents of the mixing tank a whirling motion about theaxis of rotation, this whirling motion with its resulting eddying effecttending to interfere with those movements of the liquid across the axisof rotation, and lengthwise thereof, which are necessary for thecompleteintermingling of the materials .to be mixed. Moreover, in-theoperationof rotary mixers or mixing Wheels of'the tangential type, thecentrifugal flow of the liquid through the wheel tends also to create aneddy in the stream entering the central part of the wheel, and thiseddying movement of course reduces the stream to the wheel and,consequently, the mixing action of the wheel. part due to the fact thatthe material is not brought to the opening leading to the centrifugalwheel with sufiicientvelocity to feed the wheel as fast as the wheel cande liver the material.

An object'of the invention is to provide simple and efiicient mixinmeans which will obviate the difficulties heretofore experienced inmixing operations, and will insure effective intermixing of the contentsof the mixing tank. Y

More particularly the invention aims to provide improved mixing means ofthemtary type which will operate to insure movement of the liquid acrossthe axis of rotation as well as lengthwise thereof, and at the same timewill check any tendency to bodily whirlingi of the tank contents aboutthe axis of rotation. v

An important feature of the invention is the arrangement. in the streamto the centrifugal .wheel, of means for imposing upon the stream acentripetal tendency.

Specification of Letters Patent.

This eddying is in Patented Sept.-2,1,- 1920.

Another important feature of the invent1on is the provlslon of meansabout the periphery of the rotary mixer or turbine wheel for convertingthe tangential movement of the discharged material into sub-. stantiallya radial movement. Another important feature of the inventlon is theprovision of a member located adjacent to the centrifugal wheel and soformedas to increase the-flow of material to said wheel and therebyprevent eddiesin the stream above said member.

' Other objects and important features of the invention will appear fromthe followdescription and claims when considered In connect1on,w1th theaccompanying draw in s in whichigure 1 is a vertical elevation of them1x 1ng device, the tank in which the mixing devlceis located beingshown in secton;

Fig. 3 is a section on the line- 33 Fig. 2; and

Fig. 4 is a section on the line 4'-4 Fig.2.

' 7 5 Fig. 2 is a plan of the device Referring to thedrawings, 2represents a centrifugal mixer situated at the bottom of the mixing tank4, the mixer being driven by any suitable means such as .a shaft 6connected b gearing 8 and 10 to a power shaft 12. he mixer comprises aseries of turbine blades 14 supported and carried by a ring 16, theblades 14 being arranged around the central opening in the ring. Theseblades 14 are inclined away from the direction of rotation of the {wheel0 mixer 2.

When the mixer is rotated-rapidly, the blades14 tend to" create acentrifugal flow v 1 to 3. These blades bend forwardly in the directionof rotation-of the centripetal member and also bend downwardly, theforward inclination increasing from the hub' 18 of the member, towardthe extremities of the blades. 16 tends tocreate a centrlpetal tendency1n the stream, which serves to increase the To counteract .these" Thusformed, themember amount of fluid delivered to the opening of'thecentrifugal wheel 2.

Thecentripetal member 16 and the centrifugal wheel 2 may be, andpreferably are, cast in one piece as shown in Fig. 3. i As the mixedmaterials are discharged from the periphery of the centrifugal wheel 2,they tend to travel in tangential paths across the bottom of the mixingtank 4, and then to flow up the side of the tank to a position above thewheel to replace the material drawn into the center of the wheel. Thetendency of the wheel is gradually to set up a whirling motion of theentire contents of the tank in the same direction as the rotation of thewheel. This whirling motion with its accompanying eddying effect tendsto counteract the mixing action of the wheel and to throw the entiretank contents, by

centrifugal action, to the outer wall of the tank out of range of theoperation 'of the wheel.- In order to prevent this tendency and toinsure a positive mixing of the materials and a proper direction of themixing currents, I provide a series of stationary bafile plates 20,which are preferably so 10- 'cated about the periphery of the wheel 2and at such angles to the periphery that they intersect" thetangentially moving materials and tend to direct them along radial linesas shown in Fig. 2 of thedrawing. These baffle plates may convenientlybe formed upon segmental plates 22, which can be attached by screws 24to the bottom of the tank, four of these baffle-carrying segment platesbeing shown. It will be especially noted that the baffle plates 20 arelocated close to andoutside of the path of rotation of the blades 14 ofthe centrifugal wheel 2 and are curved gradually into intersectingrelation to the tangents to the peripheral path of the blades 14; Thisparticular shape of the blades 20 gives a very eflicient action to themixer which is not the case when the blades are straight, as has beenheretofore suggested.

Having thus described my invention, what'I claim and desire to secure byLetters Patent is:

1. A rotary mixer comprising a rotary body having a central opening,means for establishing a centrifugal flow of material entering saidopening, and means interposed in the stream to said opening action to impose upon said stream, as it enters said opening, a centripetaltendency.

2. A rotary mixer comprising a rotary body -having a central opening,means traveling with said rotary body for establishing' a centrifugalflow of material entering said opening, and means located at spacedpoints about and outside the peripheral part of the path of rotation ofsaid body and curved gradually into intersecting relation to thetangents thereto, for checking the tangential movement of materialdischarged from said rotary body.

3. A rotary mixer comprising a rotary body having a central opening,blades carried by said body outside said opening and lying transverse tobut curved away from the direction of rotation of said body, otherblades located along the axis of rotation with respect to saidfirst-mentioned blades but curved in the direction of turning andprojecting over said central opening whereby said last-mentioned bladesexert a centripetal pull upon material drawn into saidopening bythecentrifugal flow created by said first-mentioned blades, and saidcentripetal blades being feathered to pull the material along the axistoward said opening.

4. A rotary mixer comprising a rotary body having a central opening,blades carried by said body outside said opening and lying transverse tobut curved away from the direction of rotation of said body, otherblades located along the axis of rotation with respect to saidfirst-mentioned blades but curved in the direction of turning andlocated above and projecting over said central opening whereby saidlast-mentioned rial drawn into said opening bythe centrifugal flowcreated by said first-mentioned blades. I

5. A rotary mixer comprising a rotary body having a central receivingopening, means for establishing a centrifugal flow of the materialreceived through said opening,

and means for preventing eddies in the stream of material, said meanscomprising a member situated adjacent to said opening bladesexert acentripetal pull upon matetrifugal flow of material thereby creating adownward stream in the material, and means for preventing eddies in saidstream, said means interposed in the downward stream of materialadjacent said rotary body and acting to create a centripetal tendency insaidstream.. i

Signed at Brooklyn, N. Y., this 9th day of January, 1919.

I JOHN JOHNSON. Witnesses:

DANIEL O. MIoHEL, MARY E. MICHEL.

